The magical, mystery 'shrooms

They're sometimes marveled at, often misunderstood.

But there are good reasons to welcome mushrooms that pop up in our yards.

November 04, 2007|By Beth Botts, Tribune staff writer

Suddenly it was there: Creamy white, delicately adorned over its satiny dome with nubbins like seed pearls, casting a tiny circle of shade in a nook of Joanie Goldberg's Glenview front yard one morning. She ran for the camera and proudly shared her photos of the mushroom with friends. "I just thought the shape of it was so cool," she says. "Out of nowhere. Almost omenlike."

It is an omen of nothing but good things. That mushroom -- Lepiota americana, fairly common in the Chicago area -- is a sign of good soil, a prosperous bustle of underground life that includes the intricate lacework of fungi. It means that in Goldberg's yard -- scattered with pine cones, leaves, honey locust pods -- there is plenty of plant matter to nurture all the subterranean organisms that work with roots to make healthy plants.

The mushroom itself is only the tip of an iceberg. It is not self-contained, like a tomato plant or a dandelion. It is a temporary mechanism for the reproduction of a much larger organism, a fungus' way of making more fungi. It just happens to be the only part of the fungus we ever see.

When a fungus is ready to reproduce and has enough moisture, it shoots up a mushroom to lift its spores into the air, even if just a fraction of an inch. From gills or pores under the cap, the minuscule spores drop and waft away in a breeze. One mushroom produces millions.

The many microscopically slender filaments of a fungus itself can twine widely through soil. There's a single fungus out in eastern Washington state that extends over at least 2,200 acres; it's believed to be more than 2,400 years old. Fairy rings, with a circle of mushrooms marking the rim of a single fungus, can sometimes be hundreds of feet wide. Yet other fungi are quite small. Scientists are using DNA to sort them out.

Often gardeners see mushrooms as just creepy weeds that infest their yards after a rainfall. "I am at my wit's end and do not know how to get rid of them," Keith Keller wrote in an e-mail to Home&Garden after a "bumper crop" appeared this summer at his home in Grafton, Wis., north of Milwaukee.

That reaction comes as no surprise to Gregory Mueller, a mycologist at the Field Museum. Mushrooms are widely misunderstood, sometimes feared and insufficiently studied. They often live in dark, damp, scary places; are occasionally poisonous; appear suddenly, often overnight, for no obvious reason; and are associated in folklore with magic and even evil. "You have mystery on top of misinformation on top of danger," Mueller says. "People are going to freak out."

Not he. A tall man from southern Illinois with a Capt. Kangaroo mustache , Mueller travels the world studying mushrooms and their underlying fungi.

He entered Southern Illinois University in Carbondale planning to be a forest ranger and stumbled across mushrooms in a botany class. "I was just fascinated by these beautiful, important organisms that we know so little about," he says.

Why are mushrooms important? Because fungi are "nature's recyclers," Mueller says. They take a major role in breaking down plant material to feed other organisms, including plants and the animals (and people) that eat them. Without fungi, Mueller says, life on land would be buried under undigested leaves and dead trees.

It a while to figure out that the mushroom is not all there is to the fungus. "It's like trying to understand how an apple tree works if all you ever see is an apple," he says.

That's one of the reasons so little is known about mushrooms. There is little baseline data on how species are distributed, for example, so scientists can watch for shifts that might be caused by climate change or see how the diversity of species is affected. That's one focus of Mueller's work, along with effects of pollution on fungi.

He's also studying the mushroom species of the Chicago region. He figures he and his students and colleagues have doubled the number of known species in the region since he arrived at the museum in 1985, and he is sure there are many more to be found.

And then there are mycorrhizae: the relationships that bind some plants to the fungi that live on their roots, passing them essential nutrients. Oaks and white pines, for example, cannot live without just the right kind of fungi.

Many of the mushrooms in the Chicago area belong to mycorrhizal fungi, Mueller says. So when pollution affects them, it affects plants we can see.

Mueller is not alone in his fascination with fungi. He is the scientific adviser to the Illinois Mycological Society, an enthusiastic group of amateur mushroom lovers who go on group forays in nearby woods to collect and compare fungi.